In certain applications, the existing or voltage signal of a pressure transmitter should never exceed and/or drop below a critical value. This can be ensured with the aid of so-called signal limiting.
Why is a signal clamping necessary in the first place?
If the pressure on a pressure transmitter lies within the nominal pressure range, then you will see a precise signal output (e.g. 4 ? 20 mA or 0 ? 10 V). However, in technical applications, it frequently happens an originally planned pressure range is exceeded or is dropped below. This can happen deliberately, for example when cleaning, along with accidentally, for instance through load variations or in the event of a fault. In these cases, the sensor signal may also move outside the defined limits, in order that, for example, a current signal in the range of 3.6 to 25 mA may appear.
If now, however, Intel are set so they recognise a signal outside of the defined limits being an error, in a few situations, trouble-free operation of the entire system cannot be ensured anymore. In these cases, a sign limiting of the pressure transmitter is practical, so that the output signal is maintained within the required range (e.g. 3.8 ? 21 mA).
Note
An example of a pressure transmitter with that your voltage signal and also the current signal could be limited may be the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.